Air circuit breaker



FIG. 1 is a front and upper left perspective view of an air circuit breaker showing our new design;

FIG. 2 is a rear and lower right perspective view thereof;

FIG. 3 is a front elevational view thereof;

FIG. 4 is a top plan view thereof;

FIG. 5 is a bottom plan view thereof;

FIG. 6 is a rear elevational view thereof;

FIG. 7 is a right side elevational view thereof;

FIG. 8 is a left side elevational view thereof;

FIG. 9 is a rear and upper right perspective view thereof; and,

FIG. 10 is a rear and upper left perspective view thereof. 

The ornamental design for an air circuit breaker, as shown and described. 